The ‘miraculous’ föhn in Bavaria of January 1704

Systematic weather observations were started in earnest in the nineteenth century when the first national weather services were established. Before the establishment of these institutions, there was a significant interest in observing the weather by individuals such as priests, writers and artists. These observations were sometimes performed unsystematically and yet there are known historical weather events which are reasonably well documented by location, date, intensity and even daily evolution. An example is the southerly fohn, one of the dominant weather phenomena in Bavaria, southern Germany. One particular event occurred on 28 January 1704, documented by Carolus Meichelbeck (1669–1734), a monk at the Monastery Benediktbeuern. He reported that this fohn rapidly melted the frozen marshes surrounding the monastery and saved the monastery from being plundered by Tyrolean troops during the Spanish Succession War. This melting was so impressive that the chronicler praised this saving of the monastery as a divine marvel, the so-called ‘Anastasia’ or ‘Lake Kochel’ miracle. In the following we will determine if realistic meteorological conditions during this fohn event would allow the reported strong and rapid melting of the water in the marshes.